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Thread: R1150RT Cold Starting Sequence

  1. #1
    Registered User roger 04 rt's Avatar
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    R1150RT Cold Starting Sequence

    It's that cold time of year here in the Northeast. I realized this week that I had some interesting data on how the Motronic manages cold starting of the R1150s that I haven't seen elsewhere. I took some time and brought it together in a single Excel spreadsheet. The Motronic is quite an orchestra conductor.

    Below is a graph that shows how the Motronic MA 2.4 with Pink Coding Plug manages the cold-start process. This chart was derived from some measurements I was making on the Yellow and Pink coding plugs, and it combines data from the GS-911 and the Innovate Motorsports LC-1. It may not be easy to digest at first but have a look at it and then see the comments beneath the chart.



    Notes on Conditions
    --The motorcycle was cold-soaked overnight and on its centerstand.
    --Temperature in my garage was about 48?? F.
    --Cold Start Lever in the detent position (which is 1.28?? open on my R1150RT).
    --Battery fully charged, alternator came on-line immediately after start.
    --LC-1 pre-powered so that it was measuring AFR at start.
    --Closed Loop AFR at Lambda=0.94 which is 13.8:1 (Using Wideband O2 Sensor)
    --Motronic MA 2.4 Pink Coding Plug (Yellow Plug may be different)

    Comments
    AFR: The first 25 seconds is very rich. At the end of the chart you can see it step to 13.8:1 which is when it goes Closed Loop.

    Injection Time: I have doubled the time because each injector fires twice per combustion cycle. During the first 25 seconds (Start Up Enrichment) the Motronic dumps a lot of fuel into the intake--8 mS at first dropping to 4 mS by the time Closed Loop operation begins. After the first 25 seconds the fuel is gradually reduced as the engine temperature comes up. The injectors are very sensitive to battery voltage during starting. If the voltage is low the injectors don't spray enough fuel for a good start.

    Spark Advance: Notice that the advance starts at about 11 degrees where it stays for about 2 minutes to help with the cold engine conditions. Then the advance is dropped into its normal idle range of about 6-8 degrees.

    RPM: For the first 2 minutes, the RPM gradually rises, even though the injection time is being reduced, as the engine warms up. Then when the Spark advance is reduced the RPM drops even though the TPS is being held constant. Note that at that 127 second moment, in addition to dropping the advance, the Motronic lengthens the injection time a bit. The RPM gradually rises until the Motronic goes Closed Loop. At that time, RPM and Injection Time are stabilized.

    Oil Temperature: I've divided the Oil Temp by 10 so that it fits on the graph. Not much to say except that it rises pretty steadily. At about 5 minutes (300 seconds) the Motronic goes Closed Loop. The Oil Temp is about 115 degrees. I don't know what combination of time and temperature the Motronic uses but it also must sense that the O2 sensor is operating, which it tells by O2 sensor voltage and resistance.

    There it is, a symphony of moving parts. A lot has to work properly in order for the Start Up sequence to work well.

    RB
    Last edited by Roger 04 RT; 12-07-2012 at 10:07 PM.

  2. #2
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    Its all managed by the pituitary and thyroid glands.
    '03 R1150R, '03 F650GS, '97DR200SE,'78 Honda CT-90, '77Honda CT-90

  3. #3
    Left Coast Rider
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    Cold Start Sequence:

    - Insert key
    - Turn to "On" position
    - Activate choke lever
    - Push "Start" button
    - Listen for exhaust sounds
    - Ride away

    Works summer AND winter.


  4. #4
    Nickname: Droid
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    Lots of interestng data. All I know is my 94 RS (which has no CAT-Code plug at all, never did), starts great even after 170k miles.

    I don't even start the bike until I am sitting on it and ready to go, in temperatures from the low 20's to high 90's. Key on, full activation of the "choke" lever, starter button, and after four cranks it fires. By the time I have my faceshield closed its ready to roll, about 30 seconds. Within a mile down the road the choke lever is full off. Been this way since Oct 94 when I first bought the bike.

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    Thanks for the post and the insight in the ECU. I just bought a 03' RT and I'm curious about the "choke" lever - why is it needed and what does it do?
    Ken S
    03 R1150RT

  6. #6
    Registered User roger 04 rt's Avatar
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    Quote Originally Posted by Nosvamos View Post
    Thanks for the post and the insight in the ECU. I just bought a 03' RT and I'm curious about the "choke" lever - why is it needed and what does it do?
    At idle, the Motronic assumes that the throttle is open 0.32 degrees.

    When you bring the Fast Idle lever to the detent, the throttle is held open to 1.28 degrees. That's all it does. If you lift the lever fully up, it opens the throttle a more to 4.16 degrees.

    It is there to provide extra air (and extra fuel via the Motronic) for starting.
    Last edited by Roger 04 RT; 12-08-2012 at 02:00 PM.

  7. #7
    Registered User GKman's Avatar
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    Switch off. Retard spark until distributor arm points at bolt. Full choke.
    Rotate slowly until up on compression. Kick hard.
    Repeat.
    Switch on. Reduce to 1/4 choke.
    Rotate slowly until up on compression. Kick hard and all the way down so a backfire doesn't feel like it broke your leg.
    Repeat as needed.

    Now that's a starting sequence. Forty years and I still remember. '53 FL

    Would like to see a discourse on getting a Bonneville running. Should take several pages before getting to the run-and-bump.

  8. #8
    Rally Rat
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    Good stuff Roger and thank you.

    I'm colorblind


    Push starter button, smile.....



    David

  9. #9
    Registered User roger 04 rt's Avatar
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    Quote Originally Posted by DROOT153718 View Post
    Good stuff Roger and thank you.

    I'm colorblind

    Push starter button, smile.....

    David
    Never thought about the colors issue.

    For the most part the Motronic does its job well and the bikes start easily.

    If you go the the left side of the chart the lines are:

    AFR
    Spark Advance
    RPM
    Injection Time
    Oil Temperature

  10. #10
    Registered User roger 04 rt's Avatar
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    Quote Originally Posted by ANDYVH View Post
    Lots of interestng data. All I know is my 94 RS (which has no CAT-Code plug at all, never did), starts great even after 170k miles.

    I don't even start the bike until I am sitting on it and ready to go, in temperatures from the low 20's to high 90's. Key on, full activation of the "choke" lever, starter button, and after four cranks it fires. By the time I have my faceshield closed its ready to roll, about 30 seconds. Within a mile down the road the choke lever is full off. Been this way since Oct 94 when I first bought the bike.
    Andy, Your description made me reread my Rider's Manual. I have been leaving the "Choke" (it's called that in the book) in the detent positionÔÇömy bike starts fine. But the book says, as you described, hold the lever fully UP until it starts. My GS-911 measures 4.16 degrees throttle when fully up and 1.28 degrees open in the detent mid-point.

    Live and learn, thanks. RB

  11. #11
    MOA #24991 Pauls1150's Avatar
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    Big "A-HA!" moment here - This clearly explains why both of my 1150s prefer(ed) to warm up for two minutes before being smooth enough to ride out. Thanks, Roger!

    (Let's NOT re-open the discourse about how some riders just start 'n' go - "per the manual"; considering that fuel is more expensive where those manuals are written, and noise/nuisance abatement is taken much more seriously there too... and it also depends somewhat on year & cat code plug.)

    GK - Yeah! I was starting my neighbor's pan for a couple of months after it severely tweaked his knee! Good lessons before I bought my first HD. Both my Trumps were "tickle SLIGHTLY and don't flood it!" The ya hope the ignition is actually sparkin'... if not, run & bump just gets y'all hot 'n' sweaty...

  12. #12
    Registered User roger 04 rt's Avatar
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    Quote Originally Posted by Pauls1150 View Post
    Big "A-HA!" moment here - This clearly explains why both of my 1150s prefer(ed) to warm up for two minutes before being smooth enough to ride out. Thanks, Roger!

    ...

    .
    The other thing I realized during the course of taking this data was that my Alternator was not coming on-line for up to 2-3 minutes at idle. BMW used to spec a 1.7W Batt bulb for the indicator but switched to 3W at some point. The bulb supplies the current that gets the rotor magnetized at startup. Alternator Bulb and Starting. My 1150 had a 3W bulb in the high beam indicator so I just switched them.

  13. #13
    MOA #24991 Pauls1150's Avatar
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    My bulb is whatever the factory put in there - I haven't looked at it yet, but yes I saw that thread. I am now very tempted to just go ahead & swap 'em too.

    Side point - it doesn't make a whole lot of sense to have a "bright" high beam indicator when you want to preserve your night vision and see further outward! Plus, that would give you a teeny bit more current available for rest of the system.

  14. #14
    Registered User roger 04 rt's Avatar
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    Quote Originally Posted by Pauls1150 View Post
    My bulb is whatever the factory put in there - I haven't looked at it yet, but yes I saw that thread. I am now very tempted to just go ahead & swap 'em too.

    Side point - it doesn't make a whole lot of sense to have a "bright" high beam indicator when you want to preserve your night vision and see further outward! Plus, that would give you a teeny bit more current available for rest of the system.
    That's what I concluded too. No need for a bright high beam bulb. The markings on my bulbs were:

    Toshiba A14V3W and Toshiba A14V1.7W.

    For my big hands they were a bear to get at.

  15. #15
    MOA #24991 Pauls1150's Avatar
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    QUESTION: Do the bulbs just pull straight out (if you're lucky & have small hands) or do they require some special finagling?

    On a tangent but somewhat related: I've also mostly painted over the illuminated red 4-way button, just another distraction.

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